The present invention relates to an apparatus for conveying and rotating wrapped or non wrapped book packs, pamphlet bundles and the like on a conveyor belt for stacking the same on a pallet or on a stacking plane in order to form individual stable stacks, said apparatus comprising a device for grasping and rotating the pack and an advancing device.
It is known that, in order to possibly palletise book packs, pamphlet bundles and the like, it is necessary to rotate one or several lines of packs forming the layers of the pallet so that the layers are tied together to a stable pack stack.
The same problems occurs in stacking devices in which packs the thickness of which is not uniform are stacked, thereby requiring to be alternately rotated by 90xc2x0 or 180xc2x0 in order to obtain a stable stack.
In the known systems, the carriage that carries the pack-rotating device in its linear translation movement is driven by a connecting rod-crank mechanism that gives rise to a harmonic motion. For this reason, the pack advancement and deposition onto a conveyor belt are performed at a different speed than that of the conveyor belt, which causes the stacks of non-wrapped book or pamphlets to be disarranged and the stability of the stacks to be impaired.
It is also known that, in order to obtain the carriage translation movement, in certain cases an arrangement is used that allows the carriage to be directly displaced in a reciprocating manner, with the disadvantage that the starting and stopping actions are abrupt and the implementation costs are high, complicated control devices being required for the proper adaptation to the various working speeds.
The apparatus of the present invention aims in particular at obtaining, in a simple way, zero relative speed between the pack grasping and rotating device and the conveyor belt onto which the packs are laid, that is, having an advancement speed of said device that is the same as the speed of said conveyor belt.